When Scott Driver began work as fire chief in Cranbrook, B.C., in 2019, his mission was crystal clear: protect his town’s residents and buildings from fire. But it wasn’t until 2022, when a wildfire threatened the mountainside that collects his town’s drinking water, that he realized that in this warming climate, his responsibilities extend far beyond the city limits.
The BC Wildfire Service was preparing to do everything it could to stop the rapidly growing flames of the Connell Ridge fire. There was just one problem, Driver says. That same slope it was about to raze, burn and dump retardants on was the main source of tap water for Cranbrook, supplying its 20,000 residents with drinking water.
That’s when a light bulb switched on for him. “Not only do I have to protect the citizens in their houses and our infrastructure, but I have to protect the ability for them to stay in their house and drink water, cause it’s a piece of life,” he recalls thinking.
He quickly brought his city’s water manager into the fire incident management team and BC Wildfire Service amended its action plan. This isn’t about houses, this is about drinking water, Driver remembers telling them.
For Scott Driver, fire chief of Cranbrook, B.C., 2022 was a pivotal year. After a wildfire threatened the mountainside that provides the town’s drinking water, he realized his job would entail more than just protecting people and buildings.
The hotter a fire burns, the more the charred soil repels water long after the flames are extinguished. That leads to more sediment washing into streams, more harmful bacteria and warmer water — all of which make it harder and more expensive to treat drinking water. One study from the peer-reviewed journal Proceedings of the National Academy of Sciences found once one-fifth of a watershed’s footprint is burned in severe fire, it will experience increased runoff and water flows, which worsens water quality downstream as the healthy soils and vegetation that absorb and filter water are burned away.
As climate change combines with decades of rapidly putting out most wildfires — leaving forests packed with dry fuel — the ripple effects are showing up in our tap water. Last summer, discoloured tap water flowing out of faucets in West Kelowna was likely caused by the wildfire that scorched the slopes feeding into the Rose Valley reservoir the previous summer, according to a city statement.
An analysis by a team of environmental scientists published earlier this year examined 245 burned watersheds across the United States and found organic carbon and phosphorus remained elevated for five years post-fire, while nitrogen and sediment levels remained elevated for up to eight years. The scientists, from the Rocky Mountain Research Station in Colorado, found nitrogen levels in the surface water from watersheds burned in the 2002 Hayman fire, the largest recorded in the state’s history at the time, were still elevated almost 15 years after the fires.
In emergency planning, responders plan around safeguarding critical infrastructure assets, but Driver sees a dangerous blind spot in B.C. when it comes to what’s considered critical. “The natural asset of a watershed isn’t currently top of mind for most,” he says. “That’s as important as the schools and the hospital.”
Wildfires are a threat to water security
Fortunately this is still a theoretical concern for Driver, but in many parts of the province, it’s already an issue. Most cities and towns in B.C. depend on reservoirs which collect surface water — the water we can see that comes from rain, melting snow, rivers, lakes and streams. There are more than 466 community watersheds in the province that supply many British Columbians with their water.
“You cannot have a community without water,” Robert Gray, a wildland fire ecologist based in Chilliwack, B.C., explains. “The reality is we’re going to be facing more and more of these kinds of crises where we’ve had a significant impact to the watershed.”
Hotter fires from a changing climate mean more soil burned and water repelled after fires are over. This can lead to sediment washing into streams and harmful bacteria that make drinking water difficult to treat.
Scott Driver sees a blind spot in B.C.’s approach to wildfire management: “The natural asset of a watershed isn‘t currently top of mind for most.”
In 2023, Canada’s worst wildfire season by a long shot, a record 2.84 million hectares burned in B.C. alone, an area almost as large as all of Vancouver Island. Of that total, 13,970 hectares burned in the Grouse Complex Wildfire that included the McDougall Creek fire in West Kelowna.
Following concerted firefighting efforts, West Kelowna’s brand new $75-million Rose Valley water treatment plant was spared, but the forested watershed which feeds the water plant was not so lucky. About 95 per cent of that watershed burned, a significant change to the landscape which has worsened water quality in the reservoir, increasing turbidity and concentrations of manganese — an unwelcome legacy expected to persist for at least five years after the burn, if not longer.
“We know the land surrounding the Rose Valley reservoir has been damaged because of the wildfire in 2023, and it means the contaminated source of water can be harder to treat because of the sediment, nutrients, metals and organic matter as a result of burned material,” Interior Health medical health officer Dr. Fatemeh Sabet told West Kelowna city council in June this year.
In 2009, one of the main watersheds that supplied water to Lillooet, B.C., burned extensively in the Mount McLean fire. As a result, its water was contaminated by ash and fire retardant and was unusable altogether. It forced the district to ban water for irrigation in the short term to stretch its reduced water capacity. Since then, the town has developed alternative water sources with the help of $10 million in federal funds.
“The frequency and intensity of the fire seasons has been overwhelming for a lot of us,” J. Ivor Norlin tells The Narwhal. As head of the drinking water systems program at B.C.’s Interior Health Authority, he’s seen an increase in impacts on water systems due to wildfires. “If it happened once in a while we might be able to focus resources. Now it’s happening every other year, or every three years, and it’s just more and more and more,” he says. In cases like West Kelowna’s McDougall Creek fire, the connection between the fire that burned in August 2023 and the rusty-coloured water with elevated manganese levels that poured out of the tap the following summer was clear. For other water quality impacts, it’s harder to connect the dots.
Canada and B.C. have seen devastating wildfire seasons in recent years. In 2023, nearly 14,000 hectares burned in the Grouse Complex Wildfire that devastated West Kelowna’s Rose Valley watershed.
Norlin says water managers are seeing the water quality in the entire Okanagan area change in recent years — everything from an increase in water temperatures to spikes in phosphorus and fine sediment have been documented. While the region saw dramatic wildfires in 2017, 2021 and again in 2023, whether these changes in the lake’s water are due entirely to wildfire, or a confluence of extreme weather events, is hard to pin down. “It’s also just part of those broader climate change impacts and just our reality of a shifting environment,” he says.
It’s not just B.C. seeing water impacts from wildfires. The fire that struck Fort McMurray, Alta., in 2016 left a huge burn scar on either side of the Athabasca River from which the town’s water is collected. “The water treatment plant there is still dealing with the effects of that fire now,” Juliette O’Keeffe, a senior scientist at the National Collaborating Centre for Environmental Health explains. “Anyone that is operating a water treatment facility has to be aware that there is always a potential for risk of a wildfire.”
“It’s not just the land that is burned; you can see downstream impacts as well. Water flows downhill.”
The path to fire-resilient watersheds — and the hurdles in the way
In the cases of West Kelowna and Fort McMurray, their plants have proven robust enough to ensure adequate water treatment despite challenges posed by downstream wildfire impacts, even if they have hiked up water treatment costs. But in Cranbrook, Driver is focused on mitigating the risks upstream, where he wants to make the land more fire-resilient in the first place.
That way, when it catches fire, it won’t burn so hot and it can bounce back more readily. “We’re not going to stop fire from hitting the landscape,” Driver says. “What we need to do is stop it from wrecking the watershed. … What we want to do is be resilient enough that we can still drink the water after the fire’s been put out.”
He and his department have already begun work to increase the resilience of the city’s water catchment, doing landscape treatments across the parcel of Cranbrook-owned forest adjacent to the town’s water reservoir. They have removed fallen logs, thinned the forest and reduced the amount of fuel available to wildfire and have plans to do more.
“We’re … planning to do logging and prescribed burning so that if a fire comes roaring down the mountain, it doesn’t come right up to the water’s edge and contaminate the reservoir of water that we use for drinking,” he explains.
Driver is focused on fire mitigation strategies before watersheds even catch flame: removing fallen logs and other wildfire fuel, thinning the forest and planning prescribed burns.
The interior Douglas fir forests surrounding Cranbrook are fire-adapted landscapes, able to recover readily from lower-temperature wildfires. Historic tree-ring analysis shows the forests in the area experienced fire every two to three decades over a period of about 250 years. Burning was a cultural practice of the Ktunaxa, who stewarded these lands for generations, using fire to renew the landscape, improve berry harvests and increase pasture. British Columbia banned cultural burns with the Bush Fire Act of 1874 – the first province in the country to do so.
In spring 2023, members of ʔaq̓am, a Ktunaxa community, and crews from BC Wildfire Service and Cranbrook’s fire department conducted a 1,200-hectare prescribed burn. A little more than two months later, wildfires whipped through the area. Driver believes the cultural burn reduced fuel loads across the landscape significantly enough to redirect the uncontrolled wildfire away from assets like the airport and neighbouring communities.
A growing body of scientific evidence shows pre-emptively burning landscapes in low-severity fires lowers their risk of experiencing high-severity fires later, including a recent study out of Stanford University which found prescribed burns lowered the severity of wildfires by 16 per cent and net smoke pollution by an average of 14 per cent. Another analysis found even greater gains of a 72 per cent reduction of severe wildfire risk if forests were thinned to reduce “ladder fuels” (vegetation that can catch fire, drawing flames from the ground up into the tree canopy) and small trees before prescribed burning.
Driver and his fire department are empowered to reduce the flammability of the parcel of land around the town’s water reservoir because it’s city-owned. But when he looks uphill to the larger watershed that Cranbrook’s citizens rely on, he’s not sure there’s any path he can pursue to make that watershed fire-resistant, because it’s on Crown land.
“What we need to do in the watersheds are fuel treatments … to mitigate or alleviate fire intensity and severity,” Gray says, adding that means thinning conifer stands, prescribed or cultural burning, converting conifer stands to hardwood or encouraging shrub fields. Most critically, it means asking the B.C. Ministry of Forests to pivot from its status quo model of timber management to more holistic ecosystem management practices that meet multiple objectives.
Currently, as both Gray and Driver note, the province will license a community to collect surface water from a watershed for its water, and with the other hand, permit a private company to harvest timber in that same watershed, with no provisions for the forestry company to log or manage that forest to mitigate its wildfire risk (whether its surface water is licensed to a community or not).
Historically, those two things — timber harvest and surface water collection — could happen in parallel without issue, but now that wildfires are threatening water security, and the best mitigation to safeguard that water source involves altering its management, the two are put in conflict. “Now your focus has to be reducing fire threat to the watershed and not just chasing timber,” says Gray. “The province should have this leadership role where they basically go to the [timber] licensee and say, the objective here in this piece is water quality and water quantity, and reduction of fire risk.”
A controlled burn reduced fuel by burning ground cover and removing larger trees in this area near Gold Creek Road in Cranbrook, B.C. The practice is proven to reduce the risk of out-of-control wildfires.
The large watershed Cranbrook, B.C., relies on is Crown land, so local fire chief Scott Driver says there are limits to what he can do to make it fire-resistant.
It’s possible for a forested watershed to be managed for both fire resilience and profitable harvests, protecting economic interests as well as water supply. In the U.S., Denver Water, the utility that provides the Denver area with clean water, spent tens of millions to repair infrastructure and remove sediment from its reservoirs in the aftermath of the 2002 Hayman Fire. It partnered with federal and state agencies in an initiative called “From Forests to Faucets” to restore fire resilience to the drainage basins that fed its reservoirs. Since 2010, the initiative has conducted treatments across 100,000 acres (roughly 40,000 hectares), ranging from planting within burned priority watersheds to fuel reduction treatments in unburned watersheds to reduce the risk of high-severity fires there.
But such an approach would require a shift in focus and new standards that the province has been unable or unwilling to negotiate for industry. “It takes an adult in the room to say, this is how we’re going to do it,” says Gray. “Right now we don’t have an adult in the room.”
In an emailed statement, the B.C. Ministry of Forests referred The Narwhal to the newly updated “Silvicultural Systems Handbook for British Columbia” as an example of how the province is “advancing innovative silvicultural practices like selective thinning, fuel management and forest restoration” to advance its understanding “of how changes to forest, water and climate will influence sustainable resource management.” However this handbook provides guidance on best practices for practitioners, rather than enforceable regulations, and provides no specific guidance on how forests that collect surface water for communities downstream should be managed to reduce the risk from severe wildfire.
The Ministry of Forests also pointed The Narwhal to its Forest Landscape Planning framework (its new forest management regime), which it writes gives “First Nations and non-Indigenous communities greater say in how forest management takes place in their community watersheds.”
And as Canada experiences its second-worst wildfire season on record, communities across B.C. are watching as their own watersheds are threatened and transformed by flames.
When it comes to watershed management, Gray says, “If you hold to your current static plan, you’re already behind the eight ball.”
Updated Sept. 15, 2025, 11:35 a.m. PT: This article was updated to correct the year of a prescribed burn near Cranbrook, B.C. The burn took place in 2023.
